Gateway device, radio communication device, charging control method, data transmission method, and computer readable medium

ABSTRACT

To provide a gateway device that achieves charging control in accordance with a RAT being used by a UE even when the UE is performing communication using different RATs at the same time, the present gateway device (30) includes a management unit (31) configured to, when a communication terminal (10) performs a first radio communication using a first radio access technology and a second radio communication using a second radio access technology, manage at least one bearer assigned to the communication terminal (10) in association with information indicating the first and second radio access technologies, and a charging system communication unit (32) configured to transmit the information indicating the first and second radio access technologies to at least one policy charging control device (40) that performs charging control.

TECHNICAL FIELD

The present disclosure relates to a gateway device, a radiocommunication device, a charging control method, a data transmissionmethod, and a program and, particularly, relates to a gateway device, aradio communication device, a charging control method, a datatransmission method, and a program using a plurality of radio accesstechnologies.

BACKGROUND ART

3GPP (3rd Generation Partnership Project), a standard specification formobile communication systems, introduces dual connectivity as atechnique for a communication terminal UE (User Equipment) to carry outwideband and low-delay communications. The dual connectivity is atechnique that allows a UE to have dual connections to a first basestation MeNB (Master evolved NodeB) and a second base station SeNB(Secondary eNB) that perform LTE (Long Term Evolution) communications,for example, so that the UE communicates not only with the MeNB but alsowith the SeNB. This improves the throughput of communications. Further,the dual connectivity is also applicable to communicationssimultaneously using a frequency band which is permitted for atelecommunications carrier to use for business and a frequency band forwhich licensing is not required (unlicensed spectrum). Furthermore, atechnique for a UE to simultaneously provide LTE communications and WLANcommunications by connection of a base station (eNB (evolved NodeB))with a wireless LAN (WLAN (Wireless LAN)) communication device is alsospecified.

Non Patent Literature 1, Section 0.1.2.8 describes, as a dualconnectivity procedure, a process flow or the like where a UE newly addsan SeNB as an eNB to communicate with the UE when the UE is beingconnected with an MeNB.

Further, areas where wireless LAN (Local Area Network) communications,which enable high-speed communications although the coverage area issmaller than that of mobile communication systems, are available havebeen expanded recently. Thus, it is feasible that a UE connects to bothan eNB that performs mobile communications and an access point WT(Wireless LAN Termination) that performs wireless LAN communications byapplying the dual connectivity technology, and the UE communicates notonly with the eNB but also with the WT. This is specifically describedin Non Patent Literature 1, Section 22A.

Note that a charging rate to be applied to a UE is determined on thebasis of a radio access technology (RAT) being used by the UE. Forexample, when a UE is performing LTE communications with an MeNB and anSeNB in dual connectivity, a charging rate determined at the time of LTEcommunications is applied to the UE. Non Patent Literature 2 describes aPCC (Policy and Charging Control) architecture for carrying out policycontrol and charging control.

Non Patent Literature 3 describes that a gateway device PGW (Packet DateNetwork Gateway) manages RAT types on a UE-by-UE basis as parametersrelated to charging. The RAT type is a parameter indicating a RAT thatis currently used by a UE.

CITATION LIST Non Patent Literature

-   NPL1: NPL1: 3GPP TS 36.300 V13.2.0 (2015-12)-   NPL2: 3GPP TS 23.203 V13.4.0 (2015-06) Section 5, Section A.4.2-   NPL3: 3GPP TS 23.401 V13.5.0 (2015-12) Section 5.7.4

SUMMARY OF INVENTION Technical Problem

In the case of executing the dual connectivity described in Non PatentLiterature 1, Section 10.1.2.8, a UE performs communications with anMeNB and an SeNB simultaneously by using one RAT. In this case, noproblem arises when RAT types as charging parameters are managed on aUE-by-UE basis as described in Non Patent Literature 3. However, NonPatent Literature 1, Section 5.7 describes, as LAA (Licensed-AssistedAccess), a technique that applies the dual connectivity tocommunications simultaneously using a frequency band which is permittedfor a telecommunications carrier to use for business and a frequencyband for which licensing is not required (unlicensed spectrum). Whencommunications are performed in this form, both communicationtechnologies are LTE and the same RAT type is used by both of thecommunication technologies. However, when considered from the viewpointthat costs for notification are reflected in charging, it is necessaryto correctly manage which of a permitted frequency band and a frequencyband for which licensing is not required (unlicensed spectrum) is used.Further, in the case where a UE performs communications using both RATs;i.e. LTE and WT, as described in Non Patent Literature 1, Section 22A,the UE performs communications using two types of RATs at the same time.Therefore, if a PGW manages RAT types on a UE-by-UE basis as describedin Non Patent Literature 3, there is a possibility that a RAT type thatis managed by the PGW and a RAT that is actually used by the UE could bedifferent. This causes a problem that, when a UE performs communicationsusing two types of RATs, it is not possible to conduct adequate chargingcontrol (apply a charging rate) in accordance with actualcommunications.

An exemplary object of the present disclosure is to provide a gatewaydevice, a radio communication device, a charging control method, a datatransmission method, and a program that achieve charging control inaccordance with a RAT being used by a UE even when the UE is performingcommunications using different RATs at the same time.

Solution to Problem

A gateway device according to a first exemplary aspect of the presentdisclosure includes a management unit configured to, when acommunication terminal performs simultaneous communications of a firstradio communication using a first radio access technology and a secondradio communication using a second radio access technology, manage atleast one bearer assigned to the communication terminal in associationwith information indicating the first and second radio accesstechnologies, and a charging system communication unit configured totransmit the information indicating the first and second radio accesstechnologies to at least one charging control device that performscharging control. When the communication terminal performscommunications simultaneously using the first and second radio accesstechnologies, communication aggregation may be formed by a radiocommunication device.

A radio communication device according to a second exemplary aspect ofthe present disclosure is a radio communication device that performs afirst radio communication using a first radio access technology with acommunication terminal, wherein, when the communication terminalperforms simultaneous communications of the first radio communicationand a second radio communication using a second radio access technology,the radio communication device transmits information associating atleast one bearer assigned to the communication terminal and informationindicating the first and second radio access technologies to a networkdevice that manages the bearer. When the communication terminal performscommunications simultaneously using the first and second radio accesstechnologies, communication aggregation may be formed by a radiocommunication device.

A charging control method according to a third exemplary aspect of thepresent disclosure includes, when a communication terminal performssimultaneous communications of a first radio communication using a firstradio access technology and a second radio communication using a secondradio access technology, managing at least one bearer assigned to thecommunication terminal in association with information indicating thefirst and second radio access technologies, and transmitting theinformation indicating the first and second radio access technologies toat least one charging control device that performs charging control.When the communication terminal performs communications simultaneouslyusing the first and second radio access technologies, communicationaggregation may be formed by a radio communication device.

A data transmission method according to a fourth exemplary aspect of thepresent disclosure is a data transmission method used in a radiocommunication device that performs a first radio communication using afirst radio access technology with a communication terminal, the methodincluding, when the communication terminal performs simultaneouscommunications of the first radio communication and a second radiocommunication using a second radio access technology, transmittinginformation associating at least one bearer assigned to thecommunication terminal and information indicating the first and secondradio access technologies to a network device that manages the bearer.When the communication terminal performs communications simultaneouslyusing the first and second radio access technologies, communicationaggregation may be formed by a radio communication device.

A program according to a fifth exemplary aspect of the presentdisclosure causes a computer to execute, when a communication terminalperforms simultaneous communications of a first radio communicationusing a first radio access technology and a second radio communicationusing a second radio access technology, managing at least one bearerassigned to the communication terminal in association with informationindicating the first and second radio access technologies, andtransmitting the information indicating the first and second radioaccess technologies to at least one charging control device thatperforms charging control. When the communication terminal performscommunications simultaneously using the first and second radio accesstechnologies, communication aggregation may be formed by a radiocommunication device.

Advantageous Effects of Invention

According to the present disclosure, it is possible to provide a gatewaydevice, a radio communication device, a charging control method, a datatransmission method, and a program that achieve charging control inaccordance with a RAT being used by a UE even when the UE is performingcommunications using different RATs at the same time.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a schematic diagram of a communication system according to afirst embodiment.

FIG. 1B is a schematic diagram of a communication system according tothe first embodiment.

FIG. 2A is a schematic diagram of a communication system according to asecond embodiment.

FIG. 2B is a schematic diagram of a communication system according to asecond embodiment.

FIG. 3 is a schematic diagram of a charging system according to thesecond embodiment.

FIG. 4 is a schematic diagram of a PGW according to the secondembodiment.

FIG. 5 is a view showing parameters managed by the PGW according to thesecond embodiment.

FIG. 6 is a schematic diagram of an eNB according to the secondembodiment.

FIG. 7 is a schematic diagram of a UE according to the secondembodiment.

FIG. 8 is a view showing a process flow of transmitting of a RAT typeaccording to the second embodiment.

FIG. 9 is a view showing parameter information set to an E-RABModification Indication message according to the second embodiment.

FIG. 10 is a view showing parameter information set to a Modify BearerRequest message according to the second embodiment.

FIG. 11 is a view showing parameter information set to a Create SessionRequest message according to the second embodiment.

FIG. 12 is a view showing parameter information set to a Bearer ResourceCommand message according to the second embodiment.

FIG. 13 is a view showing parameter information set to a Modify AccessBearers Request message according to the second embodiment.

FIG. 14 is a view showing parameter information set to a Context Requestmessage according to the second embodiment.

FIG. 15 is a view showing parameter information set to a ChangeNotification Request message according to the second embodiment.

FIG. 16 is a view showing a process flow of transmitting of a RAT typefrom a PGW to a PCRF according to the second embodiment.

FIG. 17 is a view showing a process flow of transmitting of a Diametermessage between a PCRF and a TDF according to the second embodiment.

FIG. 18 is a view to explain values of RAT types according to the secondembodiment.

FIG. 19 is a schematic diagram of a communication system according to athird embodiment.

FIG. 20 is a view to explain values of RAT types according to the thirdembodiment.

FIG. 21 is a view to explain values of RAT types according to the thirdembodiment.

FIG. 22 is a view showing parameter information set to an E-RABModification Indication message according to the third embodiment.

FIG. 23 is a schematic diagram of a radio communication device in eachembodiment.

FIG. 24 is a schematic diagram of a communication terminal in eachembodiment.

FIG. 25 is a schematic diagram of a gateway device in each embodiment.

DESCRIPTION OF EMBODIMENTS First Embodiment

Embodiments of the present disclosure are described hereinafter withreference to the drawings. A configuration example of a communicationsystem according to a first embodiment of the present disclosure isdescribed with reference to FIG. 1A.

The communication system in FIG. 1A includes a communication terminal10, a radio communication device 21, a radio communication device 22, agateway device 30, and a policy charging control device 40.

The communication terminal 10 may be a mobile phone terminal, asmartphone, a tablet terminal or the like. Further, the communicationterminal 10 may be a UE, which is used as a general term forcommunication terminals in the 3GPP. Furthermore, the communicationterminal 10 may be a terminal that performs communications using a 2G(2nd Generation mobile phone) radio access technology, a 3G (3rdGeneration mobile phone) radio access technology, an LTE radio accesstechnology, a 4G/5G (4th/5th mobile phone) radio access technology, or aradio access technology dedicated to supporting CIoT (Cellular IoT(Internet of Things)). Further, the communication terminal 10 is aterminal capable of performing simultaneous communications (dualconnections) using a plurality of different radio access technologies.For example, the communication terminal 10 may be a terminal thatperforms a mobile communication using a radio access technologyspecified in the 3GPP and a wireless LAN communication at the same time.Further, the communication terminal 10 may be a terminal that uses theLTE radio access technology and the 5G radio access technology at thesame time.

The radio communication device 21 and the radio communication device 22perform radio communications with the communication terminal 10 by usinga predetermined radio access technology (RAT). The communicationterminal 10 performs radio communications with the radio communicationdevice 22 by using a RAT different from a RAT used for radiocommunications with the radio communication device 21. When thecommunication terminal 10 performs radio communications with the radiocommunication device 21 and the radio communication device 22 by usingdifferent RATs at the same time, the radio communication device 21 andthe radio communication device 22 may separately deliver, to differentRATs, communication data transmitted from the gateway device 30 towardthe communication terminal 10, or may combine communication datatransmitted from the communication terminal 10 toward the gateway device30 by using different RATs. This operation is called communicationaggregation, hybrid dual connectivity or the like.

One RAT used in communications simultaneously using different RATs(which are referred to hereinafter as simultaneous communications) maybe LTE whose communication specifications are defined in the 3GPP, or aradio communication technology whose communication specifications willbe defined in the 3GPP in the future. This radio communicationtechnology may be called 5G or the like, for example. The other RAT usedin the simultaneous communications may be wireless LAN.

The policy charging control device 40 is a device that performs controlregarding a service policy and charging related processing related tothe communication terminal 10.

The gateway device 30 is a gateway device that is used when thecommunication terminal 10 communicates with a network to provide aservice or an external network through a network including the radiocommunication device 21 and the radio communication device 22. Further,the gateway device 30 transmits charging parameters related to thecommunication terminal 10 to the policy charging control device 40.

A configuration example of the gateway device 30 is describedhereinafter. The gateway device 30 may be a computer device thatoperates when a processor executes a program stored in a memory.

The gateway device 30 includes a management unit 31 and a chargingsystem communication unit (note that the communication unit is, in otherwords, a transmitting and receiving unit) 32. The elements thatconstitute the gateway device 30 including the management unit 31, thecharging system communication unit 32 and the like may be software, amodule or the like whose processing is executed by running, on aprocessor, a program stored in a memory. Further, the elements thatconstitute the gateway device 30 may be software such as a circuit or achip.

When the communication terminal 10 performs radio communications withthe radio communication device 21 and the radio communication device 22and forms the communication aggregation, the management unit 31 managesat least one bearer assigned to the communication terminal 10 andinformation indicating a RAT to be used for communications with theradio communication device 21 and a RAT to be used for communicationswith the radio communication device 22 in association with each other.For example, in the case where a bearer that is assigned to enable thecommunication terminal 10 to perform a communication through the radiocommunication device 21 and a bearer that is assigned to enable thecommunication terminal 10 to perform a communication through the radiocommunication device 22 are different, the management unit 31 manages abearer and a RAT in one-to-one association.

Alternatively, in the case where one bearer is assigned to thecommunication terminal 10, and a RAT to be used for communications withthe radio communication device 21 and a RAT to be used forcommunications with the radio communication device 22 are contained inone bearer, the management unit 31 manages two RATs in association withone bearer. Note that three or more RATs may be associated with onebearer.

The charging system communication unit 32 transmits, to the policycharging control device 40, information regarding RATs that are managedon a bearer-by-bearer basis in the management unit 31.

As described above, the gateway device 30 manages the RAT being used bythe communication terminal 10 in association with each bearer andthereby notifies the policy charging control device 40 of the RAT beingused by the communication terminal 10 on a bearer-by-bearer basis. Thepolicy charging control device 40 can thereby accurately grasp the RATactually used by the communication terminal 10 and perform chargingcontrol in accordance with the RAT. Further, the structure of thecommunication system, which is different from that shown in FIG. 1A, isdescribed with reference to FIG. 1B. While FIG. 1A shows the structurein which the radio communication device 22 directly connects to thegateway device 30, FIG. 1B shows the structure in which the radiocommunication device 22 connects to the gateway device 30 through theradio communication device 21.

Second Embodiment

A configuration example of a communication system according to a secondembodiment of the present disclosure is described with reference to FIG.2A. In FIG. 2A, a configuration example of a communication system thatis composed of nodes defined in the 3GPP is described. Note that, inFIG. 2A, illustration of a charging system is omitted, and the chargingsystem is described later with reference to FIG. 3.

The communication system in FIG. 2A includes a UE 50, an eNB 60, whichis a base station for LTE, a different RAT communication device 70, amobility management node MME (Mobility Management Entity) 80, a SGW(Serving Gateway) 90, a PGW 100, and a PCRF (Policy Control and ChargingRules) entity 110 (which is referred to hereinafter as PCRF 110).

The UE 50 corresponds to the communication terminal 10 in FIG. 1A. TheeNB 60 corresponds to the radio communication device 21 in FIG. 1A. Thedifferent RAT communication device 70 corresponds to the radiocommunication device 22 in FIG. 1A. The PGW 100 corresponds to thegateway device 30 in FIG. 1A. The PCRF 110 corresponds to the policycharging control device 40 in FIG. 1A.

The different RAT communication device 70 may be a base station thatsupports 5G radio communications, which are next-generation radiocommunications to be defined in the 3GPP in the future. Further, thedifferent RAT communication device 70 may be a WT (Wireless LANTermination) that performs wireless LAN communications. Furthermore, thedifferent RAT communication device 70 may be a base station thatsupports 5G radio communications using a frequency band for whichlicensing is not required (unlicensed spectrum). Although thenext-generation radio communication technology or radio accesstechnology is called 5G for the sake of making the explanation easier,it is not limited to being named 5G. Further, for easier explanation,the UE 50 is a terminal that supports both the LTE and the 5G radiocommunications.

The MME 80 is a device that mainly gives a request or an instruction formobility management and bearer setting/removal of the UE 50. The SGW 90and the PGW 100 are gateway devices that relay user data (packets)transmitted or received by the UE 50. The SGW 90 accommodates a radioaccess system, and the PGW 100 connects to an external network (PDN:Packet Data Network etc.). The PCRF 110 determines policies (chargingsystem) regarding QoS control, charging control or the like in the SGW90 and the PGW 100.

Interfaces between devices in the 3GPP are described hereinafter. AnS1-MME interface is defined between the eNB 60 and the MME 80. An S1-Uinterface is defined between the eNB 60 and the SGW 90. An S11 interfaceis defined between the MME 80 and the SGW 90. An S5 interface is definedbetween the SGW 90 and the PGW 100. A Gx interface is defined betweenthe PGW 100 and the PCRF 110. Note that the term “interface” may bereplaced by the term “reference point”.

An interface corresponding to an X2 interface, which is specified asbeing an interface between eNBs in the 3GPP, may be defined as being aninterface between the eNB 60 and the different RAT communication device70. Further, an interface corresponding to an Xw interface, which isspecified as being an interface between an eNB and a WT in the 3GPP, maybe defined as being an interface between the eNB 60 and the differentRAT communication device 70. Furthermore, an interface corresponding tothe S1-U interface may be defined as being an interface between thedifferent RAT communication device 70 and the SGW 90. Note that, in thecase where no interface is set between the 5G base station 70 and theSGW 90, the 5G base station 70 can transmit and receive data to and fromthe SGW 90 through the eNB 60.

The communication system in FIG. 2A shows that the UE 50 performs LTEcommunications with the eNB 60 and performs 5G radio communications withthe different RAT communication device 70 and forms communications usingLTE and 5G. It is assumed that a bearer when the UE 50 performscommunications through the eNB 60 is different from a bearer when the UE50 performs communications through the different RAT communicationdevice 70. Further, the structure of the communication system, which isdifferent from that shown in FIG. 2A, is described with reference toFIG. 2B. While FIG. 2A shows the structure in which the different RATcommunication device 70 directly connects to the SGW 90 using aninterface corresponding to the S1-U interface, FIG. 2B shows thestructure in which the different RAT communication device 70 connects tothe SGW 90 through the eNB 60.

A configuration example of a charging system is described hereinafterwith reference to FIG. 3. The charging system in FIG. 3 includes a PGW100, a PCRF 110, an AF (Application Function) entity 120 (which isreferred to hereinafter as AF 120), an OCS (Online Charging System) 130,a TDF (Traffic Detection Function) entity 140 (which is referred tohereinafter as TDF 140), and an OFCS (Offline Charging System) 150. Inthe charging system of FIG. 3, the PGW 100 may have a PCEF (Policy andCharging Enforcement Function) and communicate with each device thatconstitutes the charging system by use of the PCEF.

The AF 120 is an application server, and it performs control related toapplication services to be provided to the UE 50. The TDF 140 detects aservice type, for each flow, of data transmitted or received by the PGW100 through the PCRF 110. The OCS 130 and the OFCS 150 perform chargingcontrol or the like in accordance with a charging contract of the UE 50.For example, in the case of a charging contract such as a prepaidservice, the OCS 130 having the ability to monitor the traffic at alltimes performs charging processing. On the other hand, in the case of amonthly charging contract or the like, the OFCS 150 performs chargingprocessing.

Interfaces between devices in the 3GPP are described hereinafter. A Gxinterface is defined as being an interface between the PGW 100 and thePCRF 110. A Gy interface is defined as being an interface between thePGW 100 and the OCS 130. A Gz interface is defined as being an interfacebetween the PGW 100 and the OFCS 150. Gyn is defined as being aninterface between the TDF 140 and the OCS 130. Gzn is defined as beingan interface between the TDF 140 and the OFCS 150. An Sd interface isdefined as being an interface between the TDF 140 and the PCRF 110. AnSy interface is defined as being an interface between the PCRF 110 andthe OCS 130. An Rx interface is defined as being an interface betweenthe PCRF 110 and the AF 120.

The PGW 100 transmits RAT types managed on a bearer-by-bearer basis toeach device through the Gx, Gy and Gz interfaces. Further, the PCRF 110transmits RAT types managed on a bearer-by-bearer basis to each devicethrough the Rx and Sd interfaces.

A configuration example of the PGW 100 according to the secondembodiment of the present disclosure is described with reference to FIG.4. The PGW 100 includes a core network communication unit 101, amanagement unit 102, and a PCC (Policy and Charging Control)communication unit 103. The PCEF is executed by the management unit 102and the PCC communication unit 103.

The core network communication unit 101 transmits or receives user datarelated to the UE 50 to and from the SGW 90. Further, the core networkcommunication unit 101 receives, from the SGW 90, a RAT type that isused for each bearer assigned to the UE 50. The core networkcommunication unit 101 outputs information regarding the received RATtype to the management unit 102.

The management unit 102 manages the RAT type in association with thebearer assigned to the UE 50. An example in which a RAT type is added,in association with a bearer, to a list of parameters managed by the PGW100 which is specified in 3GPP TS23.401 V13.1.0 (2014-12) Table 5.7.4-1:P-GW context is described with reference to FIG. 5.

In Field shown in FIG. 5, parameters that are managed on abearer-by-bearer basis by the PGW 100 are written. In Field of FIG. 5,EPS (Evolved Packet System) Bearer ID is set. In Field written below EPSBearer ID of FIG. 5, parameters that are managed on a per EPS Bearer IDbasis are shown. EPS Bearer is a bearer that is set between the UE 50and the PGW 100.

FIG. 5 shows that the parameters that are managed on a per EPS Bearer IDbasis include a RAT type (which is shown at the bottom). In this manner,the management unit 102 of the PGW 100 manages the RAT type and the EPSBearer ID in association with each other.

Referring back to FIG. 4, the PCC communication unit 103 transmits theRAT type that is managed on a per EPS Bearer ID basis in the managementunit 102 to the PCRF 110, the OCS 130 and the OFCS 150.

Note that, also in the case where RAT types are managed on a per UE 50basis, the PCC communication unit 103 transmits the RAT type that ismanaged on a per EPS Bearer ID basis of FIG. 5, in preference to the RATthat is managed on a per UE 50 basis, to the PCRF 110, the OCS 130 andthe OFCS 150.

A configuration example of the eNB 60 according to the second embodimentof the present disclosure is described with reference to FIG. 6. The eNB60 includes a radio communication unit 61, a different RAT communicationunit 62, and a core network communication unit 63. The elements thatconstitute the eNB 60 may be software, a module or the like whoseprocessing is executed by running, on a processor, a program stored in amemory. Further, the elements that constitute the eNB 60 may be softwaresuch as a circuit or a chip.

The radio communication unit 61 performs LTE communications with the UE50. The different RAT communication unit 62 performs communications withanother radio communication device that supports a different radiocommunication scheme from LTE. In this example, the different RATcommunication unit 62 performs communications with the different RATcommunication device 70. The core network communication unit 63transmits or receives control data to and from the MME 80. The controldata may be called, for example, C(Control)-Plane data. Further, thecore network communication unit 63 transmits or receives user data toand from the SGW 90. The user data may be called, for example,U(User)-Plane. Although the core network communication unit 63 transmitsor receives control data and user data in this example, a communicationunit that transmits or receives control data and a communication unitthat transmits or receives user data may be different functional blocksor different interfaces.

The different RAT communication unit 62 carries out processing of addingthe different RAT communication device 70 as a device to formsimultaneous communications using LTE and 5G when the eNB 60 isperforming LTE communications with the UE 50.

A configuration example of the UE 50 is described with reference to FIG.7. The UE 50 includes an LTE communication unit 51 and a different RATcommunication 52. The LTE communication unit 51 performs LTEcommunications with the eNB 60. The different RAT communication 52performs 5G communications with the different RAT communication device70. The UE 50 forms simultaneous communications with the eNB 60 and thedifferent RAT communication device 70 by using the LTE communicationunit 51 and the different RAT communication 52, respectively. Further,the UE 50 is a terminal capable of performing simultaneouscommunications (dual connections) using a plurality of different radioaccess technologies.

A process flow of transmitting of a RAT type in the 3GPP according tothe second embodiment of the present disclosure is described hereinafterwith reference to FIG. 8. FIG. 8 refers to 3GPP TS23.401 V13.1.0(2014-12) FIG. 5.4.7-1. FIG. 8 shows a process flow related to E-UTRAN(Evolved Universal Terrestrial Radio Access Network) initiated E-RAB(EPS-Radio Access Bearer) modification procedure. To be specific, FIG. 8shows a process flow of transmitting a RAT type in the case where thedifferent RAT communication device 70 is added as a device to form thesimultaneous communications of LTE and 5G when the UE 50 and the eNB 60are performing LTE communications.

First, the UE 50, the eNB 60 and the different RAT communication device70 carry out processing to add the different RAT communication device 70(SCG (Secondary Cell Group) Modification) (S11). The SCG indicates abase station (or a service cell formed by the base station) that isadded to form the simultaneous communications using LTE and 5G. To bespecific, in FIG. 8, the different RAT communication device 70corresponds to the SCG. On the other hand, the eNB 60, with which the UE50 has communicated initially, corresponds to a MCG (Master Cell Group).

Next, user data is transferred between the eNB 60 and the different RATcommunication device 70 (Forwarding of data) (S12).

Then, the eNB 60 transmits an E-RAB Modification Indication message tothe MME 80 in order to update bearer information after addition of thedifferent RAT communication device 70 as the SCG (S13). The bearerinformation to be updated is E-RAB (E-UTRAN Radio Access Bearer). TheE-RAB is a bearer that is set between the UE 50 and the SGW 90. Further,the E-RAB corresponds one-to-one with an EPS Bearer that is set betweenthe UE 50 and the PGW 100.

Parameter information that is set to the E-RAB Modification Indicationmessage is described with reference to FIG. 9. Note that FIG. 9 refersto 3GPP TS 36.413 V13.0.0 (2015-06) Section 9.1.3.8. Parameterinformation that is set to the E-RAB Modification Indication message iswritten below IE/Group Name.

In E-RAB to be Modified List, parameters regarding the different RATcommunication device 70 that is added to form the simultaneouscommunications of LTE and 5G are set. For example, in E-RAB to beModified Item IEs (Information Elements), E-RAB ID for identifying E-RABto be assigned when the UE 50 communicates with the different RATcommunication device 70 is set. Further, in E-RAB to be Modified ItemIEs, RAT type (5G) indicating the RAT which the UE 50 uses forcommunications with the different RAT communication device 70 is set.For example, information indicating 5G may be set as the RAT type thatis set to E-RAB to be Modified Item IEs.

The bearer that is set between the UE 50 and the SGW 90 through thedifferent RAT communication device 70 may be called differently fromE-RAB. In FIG. 9, the bearer that is set between the UE 50 and the SGW90 through the different RAT communication device 70 is described asE-RAB for the sake of easier explanation. Further, the names E-RAB to beModified List, E-RAB to be Modified Item IEs, and E-RAB ID may bechanged in accordance with the name of the bearer that is set betweenthe UE 50 and the SGW 90 through the different RAT communication device70.

In E-RAB not to be Modified List, parameters regarding the eNB 60, withwhich the UE 50 has communicated initially, are set. For example, inE-RAB not to be Modified Item IEs, E-RAB ID for identifying E-RAB to beassigned when the UE 50 communicates with the eNB 60 is set. Further, inE-RAB not to be Modified Item IEs, RAT type (LTE) indicating the RATwhich the UE 50 uses for communications with the eNB 60 is set. Forexample, information indicating LTE may be set as the RAT type that isset to E-RAB not to be Modified Item IEs.

The eNB 60 transmits, to the MME 80, the E-RAB Modification Indicationmessage containing the RAT type associated with the E-RAB ID.

Referring back to FIG. 8, the MME 80 receives the E-RAB ModificationIndication message and transmits, to the SGW 90, a Modify Bearer Requestmessage to which the RAT type associated with the E-RAB ID is set (S14).Further, the SGW 90 transmits, to the PGW 100, the Modify Bearer Requestmessage to which the RAT type associated with the E-RAB ID is set (S15).

Parameter information that is set to the Modify Bearer Request messageis described with reference to FIG. 10. Note that FIG. 10 refers to 3GPPTS 29.274 V13.2.0 (2015-06) Table 7.2.7-2. As shown in FIG. 10, a RATtype and EPS Bearer ID are set to the Modify Bearer Request message.Further, when there are a plurality of E-RAB IDs as in the example ofFIG. 9, a plurality of Bearer Context IE Types are set to the ModifyBearer Request message, and a RAT type is set for each EPS Bearer ID.Further, the RAT type may be set for each Modify Bearer Request message.In other words, the RAT type can be set for each UE in the Modify BearerRequest message. In this case, the RAT type that is set to the ModifyBearer Request message is valid for all EPS Bearers. However, in thecase where the RAT type is set to each of the Modify Bearer Requestmessage and the EPS Bearer ID, the RAT type that is set to the EPSBearer ID may be processed in preference to the other.

Referring back to FIG. 8, as a response to the Modify Bearer Requestmessage, the PGW 100 transmits a Modify Bearer Response message to theSGW 90 (S16). Further, the SGW 90 transmits the Modify Bearer Responsemessage to the MME 80 (S17). After Step S17, the SGW 90 can transmituser data addressed to the UE 50 to the eNB 60 and the different RATcommunication device 70. Further, after Step S17, the SGW 90 can receiveuser data transmitted from the UE 50 through the eNB 60 or the differentRAT communication device 70.

Although the RAT type associated with the E-RAB ID or the EPS Bearer IDis set to the E-RAB Modification Indication message and the ModifyBearer Request message in the process flow of FIG. 8, the RAT typeassociated with a bearer may be set to another message different fromthose messages.

For example, FIG. 11 shows that a RAT type is set, for each EPS BearerID, to a Create Session Request message that is used in an ATTACHprocess, a Tracking Area Update process or the like. Note that FIG. 11refers to 3GPP TS 29.274 V13.2.0 (2015-06) Table 7.2.1-2. The MME 80transmits, to the SGW 90, the Create Session Request message that is setas above. Further, the RAT type may be set for each Create SessionRequest message. In other words, the RAT type can be set for each UE inthe Create Session Request message. In this case, the RAT type that isset to the Create Session Request message is valid for all EPS Bearers.However, in the case where the RAT type is set to each of the CreateSession Request message and the EPS Bearer ID, the RAT type that is setto the EPS Bearer ID may be processed in preference to the other.Further, the SGW 90 transmits (transfers), to the PGW 100, the CreateSession Request message that is set as above.

FIG. 12 shows that a RAT type is set, for each EPS Bearer ID, to aBearer Resource Command message that is used to request assignment of abearer or request modification of a bearer when the UE 50 adds thedifferent RAT communication device 70 and forms the simultaneouscommunications of LTE and 5G. Note that FIG. 12 refers to 3GPP TS 29.274V13.2.0 (2015-06) Table 7.2.5-2. The MME 80 transmits, to the SGW 90,the Bearer Resource Command message that is set as above. Further, theRAT type may be set for each Bearer Resource Command message. In otherwords, the RAT type can be set for each UE in the Bearer ResourceCommand message. In this case, the RAT type that is set to the BearerResource Command message is valid for all EPS Bearers. However, in thecase where the RAT type is set to each of the Bearer Resource Commandmessage and the EPS Bearer ID, the RAT type that is set to the EPSBearer ID may be processed in preference to the other. Further, the SGW90 transmits (transfers), to the PGW 100, the Bearer Resource Commandmessage that is set as above.

FIG. 13 shows that a RAT type is set, for each EPS Bearer ID, to anAccess Bearers Request message that is used in a handover process whereno change occurs in the SGW 90. Note that FIG. 13 refers to 3GPP TS29.274 V13.2.0 (2015-06) Table 7.2.24-2. The MME 80 transmits, to theSGW 90, the Modify Access Bearers Request message that is set as above.Further, the RAT type may be set for each Modify Access Bearers Requestmessage. In other words, the RAT type can be set for each UE in theModify Access Bearers Request message. In this case, the RAT type thatis set to the Modify Access Bearers Request message is valid for all EPSBearers. However, in the case where the RAT type is set to each of theModify Access Bearers Request message and the EPS Bearer ID, the RATtype that is set to the EPS Bearer ID may be processed in preference tothe other.

FIG. 14 shows that a RAT type is set, for each EPS Bearer ID, to aContext Request message that is used in a Tracking Area Update processor the like. Note that FIG. 14 refers to 3GPP TS 29.274 V13.2.0(2015-06) Table 7.3.5-1. The Context Request message is transmittedbetween an MME before change and an MME after change when the UE 50moves to a place where a change in the MME occurs. Further, the RAT typemay be set for each Context Request message. In other words, the RATtype can be set for each UE in the Context Request message. In thiscase, the RAT type that is set to the Context Request message is validfor all EPS Bearers. However, in the case where the RAT type is set toeach of the Context Request message and the EPS Bearer ID, the RAT typethat is set to the EPS Bearer ID may be processed in preference to theother.

FIG. 15 shows that a RAT type is set, for each EPS Bearer ID, to aChange Notification Request message that is transmitted from the MME 80to the SGW 90. Note that FIG. 15 refers to 3GPP TS 29.274 V13.2.0(2015-06) Table 7.3.14-1. Further, the RAT type may be set for eachChange Notification Request message. In other words, the RAT type can beset for each UE in the Change Notification Request message. In thiscase, the RAT type that is set to the Change Notification Requestmessage is valid for all EPS Bearers. However, in the case where the RATtype is set to each of the Change Notification Request message and theEPS Bearer ID, the RAT type that is set to the EPS Bearer ID may beprocessed in preference to the other.

Hereinafter, a process flow when transmitting a RAT type from the PGW100 to the PCRF 110 is described with reference to FIG. 16.

When the UE 50 forms the simultaneous communications of LTE and 5G withthe eNB 60 and the different RAT communication device 70, the PGW 100notifies the PCRF 110 that an IP-CAN (IP-Connectivity Access Network)Session is established. To be specific, the PGW 100 transmits a DiameterCCR (Credit Control Request) message to the PCRF 110 (S21). The PGW 100sets, to the Diameter CCR message, the RAT type associated with the EPSbearer. The PCRF 110 receives the Diameter CCR message and therebygrasps the RAT type associated with the EPS bearer. Further, the RATtype may be set for each Diameter CCR message. In other words, the RATtype can be set for each UE in the Diameter CCR message. In this case,the RAT type that is set to the Diameter CCR message is valid for allEPS Bearers. However, in the case where the RAT type is set to each ofthe Diameter CCR message and the EPS bearer, the RAT type that is set tothe EPS Bearer ID may be processed in preference to the other.

A process of transmitting a Diameter message between the PCRF 110 andthe TDF 140 is described hereinafter with reference to FIG. 17. The PCRF110 transmits, to the TDF 140, a Diameter TSR (TDF Session Request)message to which an ADC (Application Detection and Control) rule forextracting a specific packet flow from user data traffic regarding theUE 50 is set (S31). The PCRF 110 sets the RAT type associated with theEPS bearer to the Diameter TSR message. Further, the RAT type may be setfor each Diameter TSR message. In other words, the RAT type can be setfor each UE in the Diameter TSR message. In this case, the RAT type thatis set to the Diameter TSR message is valid for all EPS Bearers.However, in the case where the RAT type is set to each of the DiameterTSR message and the EPS bearer, the RAT type that is set to the EPSBearer may be processed in preference to the other.

After that, the TDF 140 transmits, as a response message, a Diameter TSA(TDF Session Answer) message to the PCRF 110 (S32).

Besides the examples shown in FIGS. 16 and 17, the RAT type associatedwith the EPS Bearer is transmitted to the AF 120, the OCS 130 and theOFCS 150 with use of the Diameter message. Further, the RAT type may beset for each Diameter TSA message. In other words, the RAT type can beset for each UE in the Diameter TSA message. In this case, the RAT typethat is set to the Diameter TSA message is valid for all EPS Bearers.However, in the case where the RAT type is set to each of the DiameterTSA message and the EPS bearer, the RAT type that is set to the EPSBearer may be processed in preference to the other.

Values of RAT types to be set to various messages are describedhereinbelow. Currently, in 3GPP TS 29.274 V13.2.0 (2015-06) Table8.17-1, Values 0 to 7 shown in FIG. 18 are defined as values indicatingRAT types. For example, Value 3 indicates wireless LAN (WLAN), and Value6 indicates EUTRAN (LTE). FIG. 18 shows that 8 is newly added as thevalue of the RAT type indicating 5G. It is thereby possible to set 6when LTE is indicated as the RAT type and set 8 when 5G is indicated ineach message.

As described above, the RAT type associated with the E-RAB ID or the EPSBearer ID is set to each message defined in the 3GPP and transmitted toa related node including the PGW 100. Therefore, when the UE 50 formsthe simultaneous communications of LTE and 5G, the PGW 100 can grasp theRAT type for each bearer used by the UE 50, not for each UE 50. The PGW100 can thereby carry out charging on a bearer-by-bearer basis inaccordance with the RAT type for the UE 50 that forms the simultaneouscommunications of LTE and 5G.

Third Embodiment

A configuration example of a communication system according to a thirdembodiment of the present disclosure is described with reference to FIG.19. The communication system in FIG. 19 uses an access point WT 160,which performs wireless LAN communications, in place of the differentRAT communication device 70 in FIG. 2B. Further, it is assumed that aninterface is not set between the WT 160 and the SGW 90, and the WT 160transmits or receives user data regarding the UE 50 through the eNB 60.An Xw interface is defined as being an interface between the eNB 60 andthe WT 160. The WT 160 may be an AP (Access Point) or a WiFi router thatis used as a master unit or a base station in wireless LANcommunications, for example.

The communication system in FIG. 19 shows that the UE 50 performs LTEcommunications with the eNB 60 and performs wireless LAN communicationswith the WT 160 and forms the simultaneous communications using LTE andwireless LAN. It is assumed that the eNB 60 sets a bearer that is usedfor LTE communications with the UE 50 and a bearer that is used forwireless LAN communications through the WT 160 as one bearer.Specifically, the eNB 60 sets two different RATs to one bearer andthereby forms the simultaneous communications of LTE and wireless LANwith the UE 50.

Values of RAT types to be set to various messages defined in the 3GPPare described hereinbelow. Currently, in 3GPP TS 29.274 V13.2.0(2015-06) Table 8.17-1, Values 0 to 7 shown in FIG. 20 are defined asvalues indicating RAT types. For example, Value 3 indicates wireless LAN(WLAN), and Value 6 indicates EUTRAN (LTE).

For a new RAT such as 5G wireless technology or wireless technologydedicated to CIoT (Cellular IoT (Internet of Things)) also, the type ofRAT can be represented by adding a new Value to the RAT type. Further,different Values may be added respectively to 5G wireless technologyusing a frequency of 6 GHz or less and 5G wireless technology using afrequency of 6 GHz or more. Likewise, regarding the wireless technologydedicated to CIoT also, different Values may be added respectively totechnology using a control signal for data transfer and technology usinga dedicated bearer for data transfer.

In the second embodiment, in the case where the UE 50 forms the LTE-5Gaggregation, a predetermined Value may be set for each bearer. However,in the case where the UE 50 forms the LTE-WT aggregation as in the thirdembodiment, a plurality of RATs are included in one bearer. In such acase, it may be defined that the RAT type of Value 8 indicatesEUTRAN+WLAN as shown in FIG. 20, for example. Specifically, each nodeshown in FIG. 19 may determine that the UE 50 forms the LTE-WTaggregation when Value 8 is set as the RAT type.

Alternatively, as shown in FIG. 21, it may be indicated that the UE 50forms the LTE-WT aggregation by writing values next to each other, likeValue 6+3. Note that FIG. 12 refers to 3GPP TS 29.274 V13.2.0 (2015-06)Table 8.17-1.

Further, in FIGS. 20 and 21, a usage rate, in each RAT, of user datatransmitted through one bearer may be also defined when the UE 50 formsthe LTE-WT aggregation.

For example, in FIG. 20, Value 8 may be defined as EUTRAN (30%)+WLAN(70%), and Value 9 may be defined as EUTRAN (50%)+WLAN (50%) or thelike. 30% in EUTRAN (30%) means that 30% of user data transmittedthrough one bearer is transmitted by LTE communications.

Further, in FIG. 21, a usage rate of LTE communications and WLANcommunications may be defined like Value 6 (30%)+3 (70%).

Parameter information that is set to the E-RAB Modification Indicationmessage according to the third embodiment of the present disclosure isdescribed with reference to FIG. 22. As described earlier, it is assumedin the second embodiment that E-RABs that are identified by differentE-RAB IDs are used in the eNB 60 and the different RAT communicationdevice 70 when the UE 50 forms the simultaneous communications of LTEand 5G in FIG. 9. Thus, in FIG. 9, E-RAB to be Modified List and E-RABnot to be Modified List are contained in the E-RAB ModificationIndication message.

On the other hand, in FIG. 22, it is assumed that the same E-RAB is usedin the eNB 60 and the WT 160 when the UE 50 forms the simultaneouscommunications of LTE and wireless LAN. Thus, in FIG. 9, only E-RAB tobe Modified List is contained in the E-RAB Modification Indicationmessage. In E-RAB to be Modified List, a RAT type is set in associationwith the E-RAB ID. When the UE 50 forms the simultaneous communicationsof LTE and wireless LAN, Value where the RAT types indicate EUTRAN+WLANin FIG. 20 or 21 is set as the RAT type in FIG. 22.

Further, the name of a bearer where LTE communications and wireless LANcommunications are set may be different from E-RAB, and it is notlimited to the name E-RAB.

As described above, by defining RAT types as in the third embodiment ofthe present disclosure, it is possible to accurately grasp the RAT typesthat are set to one bearer even when a plurality of RAT types are set toone bearer.

Further, by setting a usage rate of each RAT type in the case where aplurality of RAT types are set to one bearer, it is possible to carryout charging for the UE 50 in accordance with the usage rate of the RATtype in charging control.

Further, by adding, for each RAT type, information for distinguishingbetween using a frequency band which is permitted for atelecommunications carrier to use by business and using a frequency bandfor which licensing is not required (unlicensed spectrum), it ispossible to carry out charging in accordance with the usage of afrequency band which is permitted for a telecommunications carrier touse by business. For example, Value 6, which is already defined, may bedefined as UETRAN (LTE) using a frequency band which is permitted for atelecommunications carrier to use by business, and a new Value may bedefined as LAA EUTRAN (Licensed-Assisted Access EUTRAN). Alternatively,a new parameter for distinguishing between using a frequency band whichis permitted for a telecommunications carrier to use by business andusing a frequency band for which licensing is not required (unlicensedspectrum) may be specified separately from each RAT type, and chargingmay be carried out in combination with the RAT type.

It should be noted that the present disclosure is not limited to theabove-described embodiments and may be varied in many ways within thescope of the present disclosure. For example, the simultaneouscommunications of LTE and 5G in the second embodiment may be implementedby using one bearer as described in the third embodiment. Further, thesimultaneous communications of LTE and wireless LAN in the thirdembodiment may be implemented by using two bearers as described in thesecond embodiment. Further, the present disclosure may be implemented bycombining the first to third embodiments as appropriate.

Configuration examples of the communication terminal 10, the radiocommunication device 21, the radio communication device 22 and thegateway device 30 described in the plurality of embodiments above aredescribed hereinafter. FIG. 23 is a block diagram showing aconfiguration example of the radio communication device 21 and the radiocommunication device 22. Referring to FIG. 23, the radio communicationdevice 21 and the radio communication device 22 include an RFtransceiver 1001, a network interface 1003, a processor 1004, and amemory 1005. The RF transceiver 1001 performs analog RF signalprocessing for communication with the UEs. The RF transceiver 1001 mayinclude a plurality of transceivers. The RF transceiver 1001 isconnected to an antenna 1002 and a processor 1004. The RF transceiver1001 receives modulated symbol data (or OFDM symbol data) from theprocessor 1004, generates a transmission RF signal and supplies thetransmission RF signal to the antenna 1002. Further, the RF transceiver1001 generates a baseband received signal based on a received RF signalreceived by the antenna 1002 and supplies it to the processor 1004.

The network interface 1003 is used for communications with a networknode (e.g., gateway device 30). The network interface 1003 may include anetwork interface card (NIC) compliant to IEEE 802.3 series, forexample.

The processor 1004 performs data plane processing including digitalbaseband signal processing and control plane processing for radiocommunications. For example, in the case of LTE and LTE-Advanced, thedigital baseband signal processing by the processor 1004 may includesignal processing of MAC layer and PHY layer.

The processor 1004 may include a plurality of processors. For example,the processor 1004 may include a modem processor (e.g., DSP) thatperforms digital baseband signal processing and a protocol stackprocessor (e.g., CPU or MPU) that performs control plane processing.

The memory 1005 is a combination of a volatile memory and a nonvolatilememory. The memory 1005 may include a plurality of memory devices thatare physically independent of one another. The volatile memory is aStatic Random Access Memory (SRAM), a Dynamic RAM (DRAM), or acombination of them, for example. The nonvolatile memory is a mask ReadOnly Memory (MROM), an Electrically Erasable Programmable ROM (EEPROM),a flash memory, a hard disk drive, or a combination of them, forexample. The memory 1005 may include a storage that is placed apart fromthe processor 1004. In this case, the processor 1004 may access thememory 1005 through the network interface 1003 or an I/O interface,which is not shown.

The memory 1005 may store a software module (computer program)containing a group of instructions and data for performing theprocessing by the radio communication device 21 and the radiocommunication device 22 described in the above plurality of embodiments.In several implementations, the processor 1004 may be configured toperform the processing of a remote node 10 described in the aboveembodiments by reading the software module from the memory 1005 andexecuting it.

FIG. 24 is a block diagram showing a configuration example of thecommunication terminal 10. A Radio Frequency (RF) transceiver 1101performs analog RF signal processing for communication with the radiocommunication device 21 and the radio communication device 22. Theanalog RF signal processing performed by the RF transceiver 1101includes frequency up-conversion, frequency down-conversion, andamplification. The RF transceiver 1101 is connected to an antenna 1102and a baseband processor 1103. Specifically, the RF transceiver 1101receives modulated symbol data (or OFDM symbol data) from the basebandprocessor 1103, generates a transmission RF signal and supplies thetransmission RF signal to the antenna 1102. Further, the RF transceiver1101 generates a baseband received signal based on a received RF signalreceived by the antenna 1102 and supplies it to the baseband processor1103.

The baseband processor 1103 performs digital baseband signal processing(data plane processing) and control plane processing for radiocommunications. The digital baseband signal processing includes (a) datacompression/decompression, (b) data segmentation/concatenation, (c)transmission format (transmission frame) composition/decomposition, (d)transmission path encoding/decoding, (e) modulation (symbolmapping)/demodulation, and (f) OFDM symbol data (baseband OFDM signal)generation by Inverse Fast Fourier Transform (IFFT) and the like. On theother hand, the control plane processing includes communicationmanagement of Layer 1 (e.g., transmission power control), Layer 2 (e.g.,radio resource management and hybrid automatic repeat request (HARQ)processing), and Layer 3 (e.g., attach, mobility, and signaling relatedto call management).

For example, in the case of LTE and LTE-Advanced, the digital basebandsignal processing by the baseband processor 1103 may include signalprocessing of Packet Data Convergence Protocol (PDCP) layer, Radio LinkControl (RLC) layer, MAC layer, and PHY layer. Further, the controlplane processing by the baseband processor 1103 may include processingof Non-Access Stratum (NAS) protocol, RRC protocol, and MAC CE.

The baseband processor 1103 may include a modem processor (e.g., DigitalSignal Processor (DSP)) that performs digital baseband signal processingand a protocol stack processor (e.g., Central Processing Unit (CPU) orMicro Processing Unit (MPU)) that performs control plane processing. Inthis case, the protocol stack processor that performs control planeprocessing may be made common to an application processor 1104, which isdescribed below.

The application processor 1104 is also called a CPU, an MPU, amicroprocessor or a processor core. The application processor 1104 mayinclude a plurality of processors (a plurality of processor cores). Theapplication processor 1104 implements each function of the communicationterminal 10 by running a system software program (Operating System (OS))and various application programs (e.g., call application, web browser,mailer, camera control application, music playback application etc.)read from a memory 1106 or a memory, which is not shown.

In several implementations, as shown in the dotted line (1105) in FIG.24, the baseband processor 1103 and the application processor 1104 maybe integrated into one chip. In other words, the baseband processor 1103and the application processor 1104 may be implemented as one System onChip (SoC) device 1105. The SoC device is also called a system LargeScale Integration (LSI) or a chip set in some cases.

The memory 1106 is a volatile memory, a nonvolatile memory, or acombination of them. The memory 1106 may include a plurality of memorydevices that are physically independent of one another. The volatilememory is a Static Random Access Memory (SRAM), a Dynamic RAM (DRAM), ora combination of them, for example. The nonvolatile memory is a maskRead Only Memory (MROM), an Electrically Erasable Programmable ROM(EEPROM), a flash memory, a hard disk drive, or a combination of them,for example. For example, the memory 1106 may include an external memorydevice that is accessible from the baseband processor 1103, theapplication processor 1104 and the SoC 1105. The memory 1106 may includean internal memory device that is integrated into the baseband processor1103, the application processor 1104 or the SoC 1105. Further, thememory 1106 may include a memory in a Universal Integrated Circuit Card(UICC).

The memory 1106 may store a software module (computer program)containing a group of instructions and data for performing theprocessing by the communication terminal 10 described in the aboveplurality of embodiments. In several implementations, the basebandprocessor 1103 or the application processor 1104 may be configured toperform the processing of the communication terminal described in theabove embodiments by reading the software module from the memory 1106and executing it.

FIG. 25 is a block diagram showing a configuration example of thegateway device 30. Referring to FIG. 25, the gateway device 30 includesa network interface 1211, a processor 1202, and a memory 1203. Thenetwork interface 1201 is used to communicate with network nodes (e.g.,the radio communication device 21). The network interface 1201 mayinclude a network interface card (NIC) that complies with the IEEE 802.3series, for example.

The processor 1202 reads and runs software (computer program) from thememory 1203 and thereby executes processing of the gateway device 30that is described with reference to the sequence charts and theflowcharts in the embodiments described above. The processor 1202 may bea microprocessor, an MPU or a CPU, for example. The processor 1202 mayinclude a plurality of processors.

The processor 1202 performs data plane processing including digitalbaseband signal processing and control plane processing for radiocommunications. For example, in the case of LTE and LTE-Advanced, thedigital baseband signal processing by the processor 1004 may includesignal processing of PDCP layer, RLC layer, and MAC layer. Further, thesignal processing by the processor 1202 may include signal processing ofGTP-U·UDP/IP layer in the X2-U interface and the S1-U interface.Furthermore, the control plane processing by the processor 1004 mayinclude processing of X2AP protocol, S1-MME protocol and RRC protocol.

The processor 1202 may include a plurality of processors. For example,the processor 1004 may include a modem processor (e.g., DSP) thatperforms digital baseband signal processing, a processor (e.g., DSP)that performs signal processing of GTP-U·UDP/IP layer in the X2-Uinterface and the S1-U interface, and a protocol stack processor (e.g.,CPU or MPU) that performs control plane processing.

The memory 1203 is a combination of a volatile memory and a nonvolatilememory. The memory 1203 may include a storage that is placed apart fromthe processor 1202. In this case, the processor 1202 may access thememory 1203 through an I/O interface, which is not shown.

In the example of FIG. 25, the memory 1203 is used to store a group ofsoftware modules. The processor 1202 reads and runs the group ofsoftware modules from the memory 1203 and can thereby perform theprocessing of the gateway device 30 described in the above embodiments.

As described with reference to FIGS. 23 and 25, each of processorsincluded in the communication terminal 10, the radio communicationdevice 21, the radio communication device 22 and the gateway device 30runs one or a plurality of programs including a group of instructionsfor causing a computer to perform the algorithms described using thedrawings.

In the above example, the program can be stored and provided to thecomputer using any type of non-transitory computer readable medium. Thenon-transitory computer readable medium includes any type of tangiblestorage medium. Examples of the non-transitory computer readable mediuminclude magnetic storage media (such as floppy disks, magnetic tapes,hard disk drives, etc.), optical magnetic storage media (e.g.magneto-optical disks), CD-ROM (Read Only Memory), CD-R, CD-R/W, DVD-ROM(Digital Versatile Disc Read Only Memory), DVD-R (DVD Recordable)),DVD-R DL (DVD-R Dual Layer)), DVD-RW (DVD ReWritable)), DVD-RAM),DVD+R), DVR+R DL), DVD+RW), BD-R (Blu-ray (registered trademark) DiscRecordable)), BD-RE (Blu-ray (registered trademark) Disc Rewritable)),BD-ROM), and semiconductor memories (such as mask ROM, PROM(Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random AccessMemory), etc.). The program may be provided to a computer using any typeof transitory computer readable medium. Examples of the transitorycomputer readable medium include electric signals, optical signals, andelectromagnetic waves. The transitory computer readable medium canprovide the program to a computer via a wired communication line such asan electric wire or optical fiber or a wireless communication line.

While the disclosure has been particularly shown and described withreference to embodiments thereof, the disclosure is not limited to theseembodiments. It will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope of the present disclosure as definedby the claims.

This application is based upon and claims the benefit of priority fromJapanese patent application No. 2016-038830 filed on Mar. 1, 2016, thedisclosure of which is incorporated herein in its entirety by reference.

Further, the whole or part of the embodiments disclosed above can bedescribed as, but not limited to, the following supplementary notes.

Supplementary Note 1

A gateway device comprising:

a management unit configured to, when a communication terminal performssimultaneous communications of a first radio communication using a firstradio access technology and a second radio communication using a secondradio access technology, manage at least one bearer assigned to thecommunication terminal in association with information indicating thefirst and second radio access technologies; and

a charging system communication unit configured to transmit theinformation indicating the first and second radio access technologies toat least one charging control device that performs charging control.

Supplementary Note 2

The gateway device according to Supplementary Note 1, wherein thecharging system communication unit transmits, to the at least onecharging control device, a Diameter message to which the informationindicating the radio access technology is set.

Supplementary Note 3

The gateway device according to Supplementary Note 1 or 2, wherein, whena first bearer is assigned to the first radio communication and a secondbearer is assigned to the second radio communication, the managementunit manages the first bearer in association with first type informationindicating the first radio access technology, and manages the secondbearer in association with second type information indicating the secondradio access technology.

Supplementary Note 4

The gateway device according to Supplementary Note 3, wherein

the management unit further manages the first bearer and the first typeinformation in association with the second bearer and the second typeinformation, and manages the communication terminal in association withthe first type information, and

the charging system communication unit transmits, to the chargingcontrol device, the first type information associated with the firstbearer and the second type information associated with the second bearerin preference to the first type information associated with thecommunication terminal.

Supplementary Note 5

The gateway device according to Supplementary Note 1 or 2, wherein, whena third bearer is assigned to the first and second radio communications,the management unit manages the third bearer in association with thirdtype information indicating the first radio access technology and thesecond radio access technology.

Supplementary Note 6

The gateway device according to Supplementary Note 5, wherein

the management unit further manages the third bearer in association withthe third type information, and manages the communication terminal inassociation with the first type information indicating the first radioaccess technology, and

the charging system communication unit transmits, to the chargingcontrol device, the third type information associated with the thirdbearer in preference to the first type information associated with thecommunication terminal.

Supplementary Note 7

The gateway device according to any one of Supplementary Notes 1 to 6,further comprising:

a core network communication unit configured to receive a controlmessage associating at least one bearer assigned to the communicationterminal with information regarding the first and second radio accesstechnologies from a network device that performs control related totransmission of user data between the gateway device and a first radiocommunication device that performs the first radio communication and asecond radio communication device that performs the second radiocommunication.

Supplementary Note 8

The gateway device according to Supplementary Note 7, wherein thecontrol message includes at least one of a Create Session Requestmessage, a Bearer Resource Command message, a Modify Bearer Requestmessage, a Modify Access Bearers Request message, a Context Requestmessage, and a Change Notification Request message.

Supplementary Note 9

A radio communication device that performs a first radio communicationusing a first radio access technology with a communication terminal,wherein, when the communication terminal performs simultaneouscommunications of the first radio communication and a second radiocommunication using a second radio access technology, the radiocommunication device transmits information associating at least onebearer assigned to the communication terminal and information indicatingthe first and second radio access technologies to a network device thatmanages the bearer.

Supplementary Note 10

A charging control method comprising:

when a communication terminal performs simultaneous communications of afirst radio communication using a first radio access technology and asecond radio communication using a second radio access technology,managing at least one bearer assigned to the communication terminal inassociation with information indicating the first and second radioaccess technologies; and

transmitting the information indicating the first and second radioaccess technologies to at least one charging control device thatperforms charging control.

Supplementary Note 11

A data transmission method used in a radio communication device thatperforms a first radio communication using a first radio accesstechnology with a communication terminal, comprising:

when the communication terminal performs simultaneous communications ofthe first radio communication and a second radio communication using asecond radio access technology, transmitting information associating atleast one bearer assigned to the communication terminal and informationindicating the first and second radio access technologies to a networkdevice that manages the bearer.

Supplementary Note 12

A program causing a computer to execute:

when a communication terminal performs simultaneous communications of afirst radio communication using a first radio access technology and asecond radio communication using a second radio access technology,managing at least one bearer assigned to the communication terminal inassociation with information indicating the first and second radioaccess technologies; and

transmitting the information indicating the first and second radioaccess technologies to at least one charging control device thatperforms charging control.

Supplementary Note 13

A program to be executed by a computer that performs a first radiocommunication using a first radio access technology with a communicationterminal, the program causing the computer to execute:

when the communication terminal performs simultaneous communications ofthe first radio communication and a second radio communication using asecond radio access technology, transmitting information associating atleast one bearer assigned to the communication terminal and informationindicating the first and second radio access technologies to a networkdevice that manages the bearer.

REFERENCE SIGNS LIST

-   10 COMMUNICATION TERMINAL-   21 RADIO COMMUNICATION DEVICE-   22 RADIO COMMUNICATION DEVICE-   30 GATEWAY DEVICE-   31 MANAGEMENT UNIT-   32 CHARGING SYSTEM COMMUNICATION UNIT-   40 POLICY CHARGING CONTROL DEVICE-   50 UE-   51 LTE COMMUNICATION UNIT-   52 DIFFERENT RAT COMMUNICATION DEVICE UNIT-   60 eNB-   61 RADIO COMMUNICATION UNIT-   62 DIFFERENT RAT COMMUNICATION UNIT-   63 CORE NETWORK COMMUNICATION UNIT-   70 DIFFERENT RAT COMMUNICATION DEVICE-   80 MME-   90 SGW-   100 PGW-   101 CORE NETWORK COMMUNICATION UNIT-   102 MANAGEMENT UNIT-   103 PCC COMMUNICATION UNIT-   110 PCRF-   120 AF-   130 OCS-   140 TDF-   150 OFCS-   160 WT

1-13. (canceled)
 14. A communication method comprising: initiating, by abase station that connects to a communication terminal, a procedure foradding another base station that connects to the communication terminal;and sending, from the base station, a RAT (Radio Access Technology) typeon an unlicensed spectrum used for connecting to the communicationterminal by said other base station, to a mobility management apparatus.15. The communication method according to claim 14, further comprising:sending, from the mobility management apparatus, the RAT type on theunlicensed spectrum, to a gateway that relays user data of thecommunication terminal.
 16. The communication method according to claim14, wherein the RAT type on the unlicensed spectrum is used for chargingfor the communication terminal.
 17. The communication method accordingto claim 14, wherein dual connectivity or aggregation is established bysaid base station and said other base station.
 18. The communicationmethod according to claim 14, wherein said base station comprises an eNB(evolved NodeB).
 19. The communication method according to claim 14,wherein the mobility management apparatus comprises an MME (MobilityManagement Entity).
 20. A base station, comprising: a transceiverconfigured to connect to a communication terminal; a processorconfigured to initiate a procedure for adding another base station thatconnects to the communication terminal; and a transmitter configured tosend a RAT (Radio Access Technology) type on an unlicensed spectrum usedfor connecting to the communication terminal by said other base station,to a mobility management apparatus.
 21. The base station according toclaim 20, wherein the RAT type on the unlicensed spectrum is used forcharging for the communication terminal.
 22. The base station accordingto claim 20, wherein the base station establishes dual connectivity oraggregation with said other base station.
 23. The base station accordingto claim 20, wherein said base station comprises an eNB (evolved NodeB).24. The base station according to claim 20, wherein the mobilitymanagement apparatus comprises an MME (Mobility Management Entity).